Ignition-plug.



A. R. BULLOCK.

IGNITION PLUG.

APPLICATION FILED SEPT.16,190'L Patented Mar. 24, 1914.

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run STATES PATENT, OFFICE.

ARTHUR R. BULLOCK, 0F CLEVELAND, OHIO, ASSIGNOR 'I'O ARTHUR J. HUDSON, OF

CLEVELAND, OHIO.

IGNITION-PLUG.

Specification of Letters Patent.

Patented Mar. 24, 19 14..

Application filed September 16, 1907. Serial No. 893,137.

To all whom it may concern Be it known that I, ARTHUR R. BULLOCK, residing at Cleveland, in the county of Guyahoga and State of Ohio, have invented a certain new and useful Improvement in Ignition-Plugs, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to igniting or sparking plugs for explosive engines, and it has for its object the production of a device of this character in which the parts are so arranged as to reduce to a minimum the tendency of the carbon or soot to deposit on and between the terminal members and thus cause the current to be short-circuited, the provision of simple and effective means for automatically removing any such soot or carbon that tends to be thus deposited, the provision of means whereby the liability of misfiring is reduced to a minimum, and, generally, the improvement and simplification of devices of this kind.

In the accompanying drawings forming a part of this application, Figure 1 represents a central longitudinal section of an lgniting plug constructed in accordance with my invention, part of the stem being shown in elevation and the plug being shown as applied to the wall of an engine cylinder; Fig. 2 represents a side elevation of the plug;

Fig. 3 represents an elevation of the inner end of said plug, and Fig. at is a transverse sectional view taken substantially on the line 4-4- of Fig. 1.

Taking up a more specific description by reference to the drawings, in which similar reference characters designate corresponding parts throughout the several views, 1 represents a portion of the wall of an engine cylinder, the same being provided with an internally threaded opening 2, for the reception of the threaded end 3 of the outer tubular casing or shell 4 of the igniting plug. Preferably, the opening 2 and the threaded end 3 are tapered, as shown in Figs. 1 and 2. The inner end of the casing 4 is substantially closed by a plate 5, which is rigidly secured to the casing in any suitable manner, or may be made integral therewith as shown in Fig. 1, This plate is provided with an elongated opening or slot 7 having a circular enlargement 6. Beyondthe threaded portion, the

casing is provided with a squared part 8 for the application of a wrench to screw the plug into place within the engine Wall. The outer end of the squared art is provided with interior threads at 9 or the reception of a nut 10, the bore of the casing being enlarged where thus threaded so as to form an internal annular shoulder 11. lVithin the enlarged threaded part of the bore of the shell or casing, and resting against the shoulder 11 in the latter, is an annular collar 12, said collar being provided with an inwardly tapered flange 13.

(Jo-acting with the opening in the plate 5 of the casing or shell, is the spark point 14, said point forming the terminal of a metallic stem 15, said stem extending outwardly through the shell or casing and, preferably, coaxial therewith. The electrode 14 is round, as is the usual practice with respect to such electrodes, and this electrode extends through the circular enlarged portion 6 of the aperture 7, so as to be substantially equidistant from the edge thereof. Such being the case, the current discharge between the electrode and the edge of the circular enlargement 6 will be in the form of a brush discharge, which is very effective in the ignition of the explosive gases in the cylinder. Adjacent the point 14, the inner end of the stem is provided with a spiral convolution or deep screw thread 16, at the outer end of which is a flange or washer 17. Between said flange and nuts or washers 18, I surround the stems with a non-conducting sleeve 19 which prevents the short-cireuiting of the current through the plug. This sleeve is preferably formed of mica which is applied to the stem 15 in the form of disks or washers. At a suitable location to constitute a stop, the sleeve projects outwardly in the form of a flange at 20, said flange resting with its inner face upon the collar 12 and serving as a bearing on its outer face for the nut 10, the nut clamping the said flange between itself and the collar, thus holding the stem securely in position. The outer end of the stem is screw threaded to receive the washers 18 and to receive the milled thumb nut 21, between which and the washers 18 the terminal wire 22 may be secured. The other terminal wire 23 of the circuit is secured to the engine wall by a binding-post 24 in a well-known manner. The spark for ignition is produced between the point 1a and the ad jacent surface of the openlng 6.

The operation of explosive engines results in the production of a greater or less uantity of free carbon in the engine cylinder, the amount of carbon thus produced depending upon the character of'the explosive mixture employed. During the compression of this mixture, the cavity within the sparking plug is filled therewith, and, when the explosion takes place,-carbon or soot tends to collect in said cavity and, if not removed, will eventually short-circuit the current so that no spark can be produced. During the exhaust from the cylinder, the pressure within said cavity falls and the greater part of the gases therein pass out of the cavity into the engine cylinder. During the next compression stroke, and particularly at the time of explosion, the said cavity is again filled with gases under a high pressure. There i thus set up insaid cavity a vibration of gases as they pass back and forth through the opening 6 and the slot 7, the said slot being provided for the purpose of more readily permitting the passage of said gases. The said gases are heavily charged with particles of oil and with carbon, so that the latter is in a viscous or sticky condition and tends to adhere to any surface that it may touch. The sparking plug is usually very hot on the interior, and these particles of oil, when deposited, are quickly baked. For the purpose of giving the gases in the cavity a whirling or centrifugal motion so as to deposit the carbon and the oily particles on the inside of the outer casing, where they will do the least injury, the spiral convolution 16 is formed on the stem 15, the latter being in that region of the gases which is thus kept most nearly free from the carbon. The baked carbon particles eventually become dry and flaky and much of the same is carried into the cylinder with the gases so that the plug is thus kept practically free from this accumulated matter. The short-circuiting of the plug really takes place, if at all, across the mica between the collar 12 and the flange 17. The centrifugal action given to the gases by the convolution 16 very largely clears the gases from the carbon before it reaches the insulation, but some particles of the carbon will become deposited on the sleeve and may eventually result in short circuiting. It is well known that the longer the conducting surface, the greater is the resistance to any current, and for this reason I extend, as far as practical, the conducting surface on the mica within the cavity. For practical reasons, it is not desirable to extend the mica too far inward,

and the extended surface thereon is provided by forming on that part of the sleeve 19 between the flanges 20 and 17 an irregular surface-at 25, which surface may be made in the form of a spiral convolution, as shown, or it may be madeby simply forming a series of parallel grooves in the sleeve. The inwardly tapered flange on the collar 12 also assists in preventing the deposition of carbon on the mica, as the carbon is mainly deposited on the outer member 4:, and said flange, projecting over the mica, tends to prevent the carbon from reaching the inner member.

From this description, it will be seen that the sparking plug is not only simple and inexpensive, but is self-cleaning, and may be employed for a long period of time without any special attention. If, however, it should become necessary to more thoroughly cleanse the plug, this may readily be done by simply removing the nut 10, when the stem 15 and the parts carried therebymay be withdrawn from the casing 4:, after which both the stem and the casing may be cleaned in any suitable manner.

I claim 1. In an igniting plug, a terminal member comprising a stem, said stem being provided with a spiral convolution, for the purpose of imparting to the gases passing from the interior of the plug a centrifugal or whirling motion.

2. In an igniting plug, an inner member and an outer member surrounding said inner member, leaving a cavity or air space between said members, the inner member being provided with a spiral convolution, for the purpose of imparting to the gases passing from the interior of the plug a centrifugal or whirling motion.

3. In an igniting plug, the combination of a pair of terminal members, one member comprising a hollow casing that is closed at its inner end except at its center and the other member comprising a stem within said casing, said stem being provided with a sparking point cooperating with the opening at the center of the closed end of the hollow casing, and with a spiral convolution adjacent said sparking point, for the purpose of deflecting gases about to pass from the casing toward the walls of said casing.

4. In an igniting plug, a terminal member having a point at its inner end, an external terminal member surrounding the other member and being closed at its inner end except for a small opening through which the said point projects, means for. closing the outer end of the external terminal member, and a spiral convolution formed on the internal member, for the purpose of deflecting gases about to pass from the external member toward the walls thereof.

5. In an igniting plug, an internal terminal member havmg a pomt at its inner end,

an external terminal member surrounding the other member and being closed at its inner end except for a small opening through which the said point projects, means for closing the outer end 0 the external terminal member, an insulating sleeve separating said means from the internal terminal member, and a spiral convolution formed on the internal member, for the purpose of deflecting gases about to pass from the external member toward the walls thereof.

6. In an igniting plug, an outer tubular member, a plate closing the iner end of said member said plate having a central aperture and a slot extendin across said aperture, an inner member Eaving a sparking point projecting into said aperture, said inner member also having a spiral convolution thereon, for the purpose of deflecting gases about to pass from the outer tubular member toward the walls thereof, and means for closing the outer end of the tubular member and for holding the inner member in cooperative relation with the tubular member.

7. In an igniting plug, an outer tubular member, a plate closing the inner end of said member, said plate having a central aperture and a slot extendin across said aperture, an inner member having a-sparking point projecting into said aperture, said inner member also having a spiral convolution thereon for the purpose of deflecting gases about to pass from the tubular member toward the walls thereof, an insulating sleeve surrounding the inner member, and a nut for closing the outer end of-the tubular member and for holding the inner member in cooperative relation with the tubular member.

8. In an igniting plug, an outer member, an inner member arranged axially within the outer member, said inner member being provided with a spiral convolution near its inner end, an insulating sleeve surrounding the outer portion of the inner member, said sleeve being provided with a flange and with an irregular surface beyond said flange upon which carbon may be deposited, and means cooperating with said flange for holding the inner member in cooperative relation with the outer member.

9. In an igniting plug, an outer, metallic, tubular member that is adapted for attachment to the wall of an engine, said member having a plate substantially closing its inner end, said plate being provided with a central aperture and a slot extending across said aperture, the tubular member being also provided with an internal shoulder and with internal threads beyond said shoulder, a collar that is adapted to be inserted into the opening end of the tubular member and to rest upon said shoulder, an internal member, the inner end of which is provided with a sparking point and with a spiral convolution adjacent said point for the purpose of deflecting gases about to pass from the tubular member toward the walls thereof, -a flange on the internal member that is adapted to rest upon said collar, and a nut for screwing within the open end of the tubular member for pressing the said flange between itself and the said collar, substantially as and for the purpose specified.

10. In an igniting plug, an outer tubular member that is adapted for attachment to the wall of an engine, said member having a plate closing its inner end, said plate being provided with a central aperture and a slot extending across said aperture, the tubular member being also provided with an internal shoulder and with internal threads beyond said shoulder, a collar that is adapted to be inserted into the open end of the tubular member and to rest upon said shoulder, an internal member, the inner end of which is provided with a sparking point and with a spiral convolution adjacent said point, an insulating sleeve surrounding the inner member beyond said spiral convolution, said sleeve having an external flange that is adapted to rest upon said collar, that portion of the'sleeve between said flange and the spiral convolution being also provided with a spiral convolution, and a nut for screwing within the open end of the tubular member for pressing the said flange between itself and the said collar, substantially as and for the purpose specified.

11. In an igniting plug, a shell and a member within said shell, there being a space provided between the shell and member and means within the shell for imparting a centrifugal motion to outgoing gases, whereby the said gases are deflected toward the shell.

12. In an igniting plug, a shell and a member within said shell, there being a space provided between said shell and member, and means upon the inner member for imparting a centrifugal motion to the outgoing gases, thereby deflecting same toward the shell.

13. In an igniting plug, a shell and a member within said shell, there being a space provided between the shell and member, the inner end of said shell being closed except for an opening with which the said member cooperates and a slot which permits the passage of gases and means within a shell for imparting to the outgoing gases a centrifugal motion thereby deflect ing them toward the shell.

14. In an igniting plug, a combination of a shell and a member within said shell, the inner end of said shell being closed except for an opening with which the said member cooperates and a slot which permits the passage of gases, said member being provided with a sparking point whichcofiperates with In testimony whereof, I hereunto aifix my the opening in the end of the shell, said signature in the presence of two wltnesses terminal member being also provided with ARTHUR R BULLOCK a spiral convolution adjacent said sparking point for the purpose of imparting to. the Witnesses: outgoing gases a centrifugal motion, thereby S. E. Fours, deflecting them toward the wall of the shell. GEO. R. CROWN. 

